Journal of Geosciences, 66 (2021), 243–262

DOI: 10.3190/jgeosci.336

Original paper

Amphibole and pyroxene as indicators of alkaline conditions inbanded carbonatite-like marbles from Bližná, Český Krumlov Unit,
Moldanubian Zone
Pavlína RADKOVÁ1,2*, Milan NOVÁK1, Jan CEMPÍREK1, Stanislav HOUZAR3, Radek ŠKODA1
Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic;
radkova4@uniba.sk
2
Department of Mineralogy, Petrography and Geology of Mineral Deposits, Faculty of Natural Sciences, Comenius University,
Ilkovičova 6, 842 15 Bratislava, Slovakia
3
Department of Mineralogy and Petrography, Moravian Museum, Zelný trh 6, 659 37 Brno, Czech Republic*
Corresponding author
1

Amphiboles and diopside occur in several distinct mineral assemblages in banded carbonatite-like marbles from theBližná graphite mine, Český Krumlov Unit, Moldanubian Zone. The carbonatite-like marble is interlayered with dominant ordinary metacarbonates as a single continuous stratabound layer, up to 3–4 m thick. It is enriched in elements
typical for carbonatites (REE, Y, Th, Sr, Nb, Zr, and Mo) and contains accessory betafite-pyrochlore and uranothorite
along with molybdenite, sulfides (e.g., pyrite, pyrrhotite) and oxides (e.g., magnetite, ilmenite). Detailed study of thinsections in optical microscope and BSE images as well as results of EMPA revealed three distinct mineral assemblages– richterite + forsterite (RF) assemblage (Rht + Fo + Cal ˃ Dol ˃ Phl + Di), Na‑rich actinolite + diopside (AD) assemblage(Di + Act + Rht + Cal ˃ Phl) and magnesio-hastingsite + diopside (HD) assemblage (Mhst + Di + Cal ˃ Ab + Phl). The
distinct amphibole species found within the individual assemblages exhibit complex textural relations and crystallized in several prograde and retrograde stages. The following amphibole species were recognized in the individual
assemblages: RF – (richterite > ferri-winchite > tremolite, edenite), AD – (actinolite > ferri-winchite; richterite > ferri-katophorite; magnesio-riebeckite), HD – (magnesio-hastingsite; ferri-winchite, actinolite). They differ especially in
Mg/(Mg + Fetot) ratio and concentrations of F. Diopside contains up to 17 mol. % of the aegirine component and albite isFe, Ba-enriched (≤ 0.69 wt. % BaO and ≤ 0.50 wt. % Fe2O3tot). The composition of amphiboles and pyroxenes indicatesthe alkaline environment of their formation; unusually high Fe2O3 contents in albite plagioclase have known counterpartsin alkaline pegmatites and some carbonatite dykes. The following options of potential origin of the carbonatite-likemarble from Bližná are discussed: (i) metacarbonates potentially with Na- and Na,Ca-carbonates and sulfate admixture;(ii) admixture of alkaline volcanodetritic component during carbonate sedimentation; (iii) metamorphosed carbonatites
enclosed in ordinary sedimentary metacarbonate; (iv) Na-rich metasomatites characterized by mineral assemblages with
Na,Fe,F-enriched amphiboles, diopside with high aegirine component and albite. With regard to the observed mineral
assemblages, textures and composition of minerals, we can exclude (i) marine evaporates, whereas the other options (ii),(iii) and (iv) are, in general, possible. The amphiboles observed in the Bližná carbonatite-like marble are unique within
the Bohemian Massif and distinctly different from amphiboles found in metacarbonates with evaporite component.
Keywords: alkali amphibole, pyroxene, carbonatite-like marble, Český Krumlov unit, Moldanubian Zone, Bohemian Massif
Received: 16 August 2021; accepted: 8 December 2021; handling editor: J. Kotková

1. Introduction
Amphiboles are typical accessory to major rock-forming
minerals in metacarbonates from supracrustal complexes
metamorphosed from greenschist to granulite facies.
Calcic amphiboles (tremolite, actinolite, magnesio-hornblende, edenite, pargasite, magnesio-hastingsite) are dominant in metacarbonates of sedimentary origin (e. g., Deeret al. 1997), whereas sodic-calcic amphiboles (richterite,
winchite) and sodic amphiboles (magnesio-riebeckite,riebeckite, arfvedsonite) occur along with aegirine-richclinopyroxene in specific carbonate lithologies including
a variety of carbonatites s. l. (e.g., Mitchell 2005; Martin2007). Alkali-rich amphiboles and pyroxenes from carbonatites s. s. were studied in detail in numerous papers(e.g., Reguir et al. 2012 and references therein; Chudy
2013) whereas amphiboles and pyroxenes from metacarbonates enclosed in evident sedimentary lithologies with
geochemical signature distinct from ordinary marbles
have been examined only sporadically (e.g., Houzar 2004;
Houzar et al. 2017), or for special purposes such as research of marble-hosted gem deposits (e.g., Dzikowski etal. 2014; Garnier et al. 2005, 2008; Feneyrol et al. 2012).
Banded carbonatite-like marble interlayered with dominant ordinary metacarbonates from Bližná, Český Krumlov
Varied Unit, Moldanubian Zone, is enriched in elementswww.jgeosci.org

Pavlína Radková, Milan Novák, Jan Cempírek, Stanislav Houzar, Radek Škoda

Fig. 1 Schematic geological map of the Bližná surroundings, Český Krumlov Unit. Modified from Vrána et al. (2010).

typical for carbonatites (REE, Y, Th, Sr, Nb, Zr, and Mo)
and contains accessory betafite-pyrochlore, uranothorite
and molybdenite along with other accessory minerals(Šarbach et al. 1985; Veselovský et al. 1987; Drábek et al.
1999; Drábek and Stein 2015; Novák et al. 2012; Radková
2017). We examined textural relations, mineral assemblages and chemical composition of abundant amphibole andminor pyroxene and olivine from this unique carbonatitelike marble to reveal their compositional variability andgeochemical signature in relation to ordinary carbonatites(Reguir et al. 2012 and references therein). A possible
origin of the carbonatite-like marble protolith is discussed.

2. Geological setting

2.1. Lithology of the Český Krumlov Varied
Unit
This area is built by medium- to high-grade plagioclase–biotite paragneisses with common intercalationsof metacarbonates (marbles to silicate-rich and graphite244

bearing marbles), quartzitic and graphite paragneisses,
calc–silicate rocks and locally of amphibolites and amphibole gneisses (Fig. 1). A sedimentary origin of marbles
in an oxidic shallow marine environment is significantly
prevalent and well documented (Čížek et al. 1984; Suk
1974). The rocks belong to the metasedimentary complexof the Drosendorf Unit (e.g., Zoubek et al. 1988; Jenček
and Vajner 1968; Högelsberger 1989; Cháb et al. 2008;
Vrána et al. 2010; Houzar et al. 2017). Organic matterand hydrogen sulfide accumulated in local anoxic conditions from lagoons were transformed to graphite layers(Hladíková et al. 1993; Schrauder et al. 1993). The
Paleozoic age of the Drosendorf Unit is frequently presumed; however, an early Neoproterozoic protolith ageof 800–900 Ma was inferred for the analogous marblesof the Drosendorf Unit in Austria, based on their low
87
Sr/86Sr ratios (Frank et al. 1990, 1992).

2.2. Metacarbonates from Bližná
In the abandoned Václav graphite mine near Bližná,Drábek et al. (1999) distinguished three distinct types ofAmphibole and pyroxene in carbonatite-like marbles from Bližná

Fig. 2 Banded carbonatite-like marble, the third level of the Václav
graphite mine. The dark layers are silicate-rich; note detailed foldingof the rock.

metacarbonates based on their geochemistry, bulk mineral
assemblages, and the isotopic composition of Sr, C and
O: (i) Ordinary marble (OM) similar to other marbles
within the Český Krumlov Varied Unit, (ii) carbonatitelike marble (CLM), and (iii) transitional marble (TM).
The latter two occur as a single continuous strataboundlayer, up to 3–4 m thick, only in the close footwall of thegraphite horizon on the 3rd level of the mine across the
air pit K10 (Fig. 2).
The abundant (i) ordinary calcite to calcite-dolomite
marbles (OM), locally banded, with common silicates(tremolite, phlogopite, diopside, forsterite, chlorite) andpyrite, pyrrhotite, and graphite, form large nodular bodies up to 30 m thick (Vrána et al. 2010). Based on their
textural, mineralogical and geochemical characteristics,
they were interpreted as metacarbonates from a shallow
marine environment (Houzar et al. 2017).
Rare (ii) carbonatite-like calcite marbles (CLM) are
texturally heterogeneous and commonly rich in silicates(amphiboles, phlogopite, diopside, forsterite, antigorite,
talc; Drábek et al. 1999). They are characterized by highly heterogeneous chemical composition with variable but
locally very high concentrations of Mo, Nb, Zr, Th and
REE (Drábek et al. 1999, 2017; Drábek and Stein 2015;
Novák et al. 2012). Sulfide-rich portions with pyrrhotite,
pyrite, molybdenite, chalcopyrite, galenite, and sphalerite
are somewhat randomly distributed. In contrast, locallycommon accessory REE-minerals (Th, REE-rich betafite,uranothorite), fluorapatite, ilmenite with rare columbite
inclusions, and zircon are concentrated in a single layer(Radková 2017). Molybdenite dated using Re–Os method
at ~495 Ma records regional amphibolite-facies metamorphism (Drábek and Stein 2003).
Rare (iii) calcite to calcite-dolomite marbles with transitional composition between CLM and OM (transitional
marble; TM) have mineralogy similar to (ii) except thatthey contain moderate to low concentrations of Mo, Nb,
Zr and REE only (Drábek et al. 1999). Abundant calcite to calcite-dolomite marbles (OM) from the Český
Krumlov Unit, including locality Bližná with tremolite,
forsterite and diopside have been interpreted as metacarbonates from a shallow-marine lagoonal environment,
locally with evaporite admixture due to the presence ofCl-rich scapolite (Kadounová 1987; Kříbek 1988; Kříbek
et al. 1997), whereas CLM and TM were suggested tocontain variable quantities of volcanodetritic materials
derived from alkaline volcanism (Drábek et al. 1999,2017). However, alkaline metabasites or other alkaline
rocks have not been found in the Černá region. Moreover,metacarbonate bodies with carbonatite-like geochemicalsignature are known from Muckov, the Český Krumlov
Unit (Fig. 1), where a single marble sample yielded elevated contents of Zr, Nb, U, Th and REE (Houzar andNovák 2002).

3. Methodology

3.1. Samples
Amphiboles and associated minerals were studied in thinsections obtained from a large fragment of banded metacarbonate collected in the Václav graphite mine, Bližná.
The fragment consists of carbonatite-like marble (CLM)
and transitional marble (TM) using the terms proposed by
Drábek et al. (1999). Seven thin sections were preparedfrom the fragment (Fig. 3).

3.2. Chemical composition
Minerals of distinct bands in metacarbonate wereanalyzed with a Cameca SX100 electron microprobe inwavelength-dispersive mode at the Joint Laboratory ofElectron Microscopy and Microanalysis of the Department of Geological Sciences, Masaryk University, Brno,
Czech Republic. Silicates and carbonates were analyzed
at accelerating voltage of 15 kV, beam current of 10 nA,
and beam diameter 5 μm, using following standards:
Na (albite); K, Al, Si (sanidine); Ca (wollastonite); Sr(synthetic SrSO4); Ba (synthetic BaSO4); Ti (titanite);Mg (forsterite); Mn (spessartine); Fe (almandine); Zn(gahnite); Ni (synthetic Ni2SiO4); Cr (chromite); F (topaz); Cl (vanadinite); Sc and V (synthetic ScVO4). Major
elements were measured 10 to 20 s and the minor andtrace elements 40 and 60 s, respectively, on the peak
and a half of the peak time for background counts on
high- and low-energy sides of the peak. Raw data wereconverted into concentrations using appropriate X-PHI
matrix corrections (Merlet 1994). All abbreviations ofmineral names are according to Warr (2021).
245

Pavlína Radková, Milan Novák, Jan Cempírek, Stanislav Houzar, Radek Škoda

Fig. 3 Large fragment of banded metacarbonate; the position of the individual
thin sections is marked.

Tab. 1 Mineral assemblages and amphibole proportions of individual samples. a – major phases of mineral assemblages.
assemblage & sample
RF

BLC 1
BLC 2
BLC 4

Cal
A
A
A

AD

BLC 3
BLC 6

A
A

Dol
C
C
R

Fo
A
A
C

Di
R

C
A

primary minerals
Phl
Rht
Act
R
A
A
C
A

R

A
C

Ba-Phl Mhst

A
A

Ab

Mrbk

secondary minerals
Fwnc
Tlc
Srp
C Fo
C Fo
A Fo, Rht

C

R Act

Chl
R Phl

C Di, Rht
R Phl

BLC 5
A
A
R
A
R
C Mhst
R Di
BLC 7
A
C
R
A
C
C MhstR Di
A = abundant, C = common, R = rare; upper index mineral abbreviations with secondary minerals indicate the replaced primary phase.
HD

Tab. 1b – proportions of the amphibole species.
assemblage & sample
BLC 1
RF
BLC 2
BLC 4

richterite
Rht ~ Ed
Rht ˃ Tr ˃ Fwnc, Ed
Rht ˃˃ Fwnc

actinolite

AD

BLC 3
BLC 6

Rht
Rht

Act ˃ Fwnc
Act ˃ Fwnc

HD

BLC 5
BLC 7

4. Results
The individual bands differ in grain size, textures andmainly in mineral contents (Tab. 1a) and the chemical
246

magnesio-hastingsite

magnesio-riebeckite

ferri-winchite

Mrbk

Mhst ˃˃ Fktp
Mhst ˃˃ Fktp

Fwnc>>Act
Fwnc>>Actcomposition of rock-forming minerals (amphiboles,
pyroxene, olivine and phlogopite). Several amphibole
species (Leake et al. 1997, Hawthorne et al. 2012) wereidentified (Tab. 1b); more details about the chemical

Amphibole and pyroxene in carbonatite-like marbles from Bližná

compositions are given in section 4.2. Detailed study ofthin sections using an optical microscope and BSE images, as well as results of EMPA, revealed three distinct
mineral assemblages named according to the dominantprimary mineral assemblage – richterite + forsterite assemblage (RF), Na-rich actinolite + diopside assemblage(AD) and magnesio‑hastingsite + diopside assemblage(HD). Due to the heterogeneous compositions of amphiboles, we used the name of the dominant amphibole
species in the descriptions of the defined mineral assemblages (Tab. 1a,b).

4.1. Mineral assemblages of the bandedcarbonatite-like marble
The richterite + forsterite assemblage (samples BLC 1,
BLC 2, and BLC 4; Fig. 3) occurs in fine- (~0.5 mm) tomedium-grained (~2 mm) marble bands. Their characteristic overall mineral assemblage is Rht + Fo + Cal ˃ Dol ˃
Phl + Di. The rock shows parallel layers of Fo + Cal + Dol
and Rht + Cal + Dol, both usually ~5–10 mm thick, in a

carbonate-dominated matrix (see also Tab. 1). The occurrence of minor dolomite and common forsterite is distinct
from the other assemblages (Tab. 1). Dolomite mainly
occurs as subhedral grains, often adjacent to silicates(Fig. 4a,b), or in fine-grained symplectite together withcalcite (Fig. 4b). Microscopic symplectites of Cal + Dol often surround richterite (Fig. 4c) and only scarcely enclose
forsterite (Fig. 4d). In sample BLC 4, Fe-rich forsterite wasalmost completely replaced by Fe-rich serpentine (Fig. 4d);serpentinization is not as strong in the Fe-poor forsterite insamples BLC 1 and BLC 2. Richterite forms equidimensional to long prismatic subhedral grains locally associatedwith subhedral equidimensional Fe-rich forsterite. The
textural relationships of the two minerals do not indicate
any apparent replacement features (Fig. 4b). Accessory
minerals include interstitial sulfides (Tab. 2), which arevery common in thin sections BLC 1 and BLC 2. Phlogopite, molybdenite, oxide minerals and barite occur solely
in the thin section BLC 4 (Tab. 2).
The Na-rich actinolite + diopside assemblage (samples BLC 3, BLC 6) exhibits relatively large grain size

Fig. 4 BSE images of richterite-forsterite assemblage. a –, b – are taken from the BLC 2 sample. c –, d – from BLC 4 sample. Note the alterationof forsterite and amphibole by the serpentine and textural equilibrium of forsterite and amphiboles.

247

Pavlína Radková, Milan Novák, Jan Cempírek, Stanislav Houzar, Radek Škoda

Tab. 2 Assemblages of accessory minerals.
assemblage & sample
betafite
ilmenitemagnetitecolumbite
pyritepyrrhotite
molybdenite
galenitechalcopyrite
native Bi
apatitemonazite
xenotimethoritezirconbaritecelsian

BLC 1

x
x
x
x
x

RF
BLC 2

x
x
x
x
x

AD
BLC 4

x
x
x
x

HD

BLC 3
x
x
x
x
x
x
x

BLC 6

x
x

x

x

x

x
x
x

(~2–5 mm), complex textural relations and two distinct
mineral associations distributed rather randomly within
the thin sections. The association Di + Act + Rht + Cal ˃
Phl is dominant, whereas the association Act + Cal is lesscommon. Small euhedral to subhedral grains of richterite
are often enclosed in large subhedral grains of pale green
diopside, up to 4 mm in size, and both minerals are in
textural equilibrium (Fig. 5a). However, local replacement of diopside by anhedral to subhedral richterite toNa-rich actinolite was also observed (Fig. 5b,c). Subhedral grains of Na-rich actinolite that occur separated
from diopside in the association Act + Cal have diffuse
zoning with Fe-enriched, Na-depleted rims, and they are
locally replaced by ferri-winchite (Fig. 5d). Long prismatic grains of Na-rich actinolite are locally overgrownby bluish-black magnesio-riebeckite with strong pleochroism (X = bluish, Y = blue, Z = deep blue) also forms
quite a large individual bluish-black acicular crystals
and fibrous aggregates. Locally, magnesio-riebeckite is
associated with talc (Fig. 5e). Diopside locally exhibits
an irregular patchy Na,Fe-zoning near its replacementby amphibole (Fig. 5c). Phlogopite is locally replacedby chlorite. The rich assemblage of accessory minerals
includes sulfides, fluorapatite, betafite-pyrochlore, anduranothorite (Tab. 2, Fig. 5f).
The magnesio-hastingsite + diopside assemblage(samples BLC 5, BLC 7) is coarse-grained (~3–6 mm)
and the primary mineral assemblage Mhst + Di + Cal
˃ Ab + Phl is rather variable, diopside may locallyprevail over magnesio-hastingsite; both minerals exhibit moderate pleochroism in green colors. Magnesiohastingsite forms elongated subhedral to euhedralgrains (Fig. 6a,b,d) and contains small inclusionsof Ba,Fe-rich phlogopite and molybdenite (Fig. 6a).
248

BLC 5

BLC 7

x

x
x
x
x

x

x
x
x

x
x
x
x
x
x
x
x

Magnesio-hastingsite is scarcely
replaced by ferri-winchite, actinolite (Fig. 6b) and locallyalso by serpentine. Subhedral
to anhedral grains of albite areoften adjacent to (Fig. 6d) or
replaced by prismatic grains ofmagnesio-hastingsite. Albite isalso enclosed in calcite; it locally contains inclusions of zircon(Fig. 6e). Ba,Fe-rich phlogopite is typically enclosed inmagnesio-hastingsite (Fig. 6a)and locally replaced by chlorite.
Euhedral flakes of molybdenite,
up to 7 mm in size, along withaccessory fluorapatite, uranothorite (Fig. 6f) and sulfides, arecommon (Tab. 2).

4.2. Chemical composition of amphiboles,
pyroxene and associated minerals
4.2.1. Amphiboles
The heterogeneity of the rock is also reflected in thecomposition of amphiboles. Different amphibole species
are found in separate layers and within the individual assemblages and as single grains. They differ primarily in
Mg/(Mg + Fetot) ratio and concentrations of F, Fe3+ and Na.
Representative amphibole analyses are provided in Tab. 3.
To report results, we use the most recent IMA amphibole
supergroup classification and nomenclature (Hawthorne
et al. 2012; Fig. 7a–d); in the discussion, we compare theresults with the earlier classification (Leake et al. 1997)
that uses Si content instead of Fe3c+alc + Al + 2Ti (Fig. 7e–g).
The richterite + forsterite assemblage is characterized by the dominance of Na–Ca amphiboles represented
by richterite and very rare ferri-winchite (Fig. 7, 8;
Tab. 3). They are enriched in F = 0.612–0.792 apfu andthe Mg/(Mg + Fetot) ratio is high (0.927–1.000). They are
relatively poor in Al (≤ 0.389 apfu) and Ti (≤ 0.039 apfu).
Quite rare tremolite and edenite were identified as the
only Ca-amphiboles. However, their composition withelevated (Na + K)tot = 0.881–1.211 apfu and F = 0.535–
0.709 apfu is very close to that of Na–Ca amphiboles.
Sodium-calcium amphiboles are also present in the
Na-rich actinolite + diopside assemblage. Richterite toferri-katophorite commonly replace diopside and arecompositionally very similar to the richterite from the
RF-assemblage; they differ by slightly higher C(Al + Fe3+)and lower Mg/(Mg + Fe tot) ratio of 0.818–0.914 only
(Tab. 3). This association is typically characterized byclusters of Na-rich actinolite (Ca-amphibole) with diffuse

Amphibole and pyroxene in carbonatite-like marbles from Bližná

Fig. 5 BSE images of actinolite-diopside assemblage; a –, e –, f – are from the BLC 3 sample, b –, c –, d – from the BLC 6 sample; note replacement of zoned diopside by actinolite in (c), zoned amphibole in (d), and magnesio-riebeckite rims around actinolite in (e).

zoning that grades to ferri-winchite (Na–Ca-amphibole)at crystal rims. The content of F is variable (0.194–0.686
apfu), but generally lower than in richterite. Commonly,
actinolite and ferri-winchite have very contrasting rims
consisting of magnesio-riebeckite, which belongs to Naamphiboles. It is the only member of this subgroup in

the studied samples. Compared to the other amphiboles,
magnesio-riebeckite has a dramatically higher content
of BNa reaching up to 1.873 apfu, and significantly highFetot = 2.580–2.932 apfu. The ratio of Fe3+/(Fe3+ + Fe2+)calc.
ranges between 0.606 and 0.731. Fluorine concentrations
are typically low ≤ 0.180 apfu.
249

Pavlína Radková, Milan Novák, Jan Cempírek, Stanislav Houzar, Radek Škoda

Fig. 6 BSE images of hastingsite-diopside assemblage. a –, b –, c –, e –, f – are from BLC 7 sample, d – from BLC 5.

Magnesio-hastingsite + diopside assemblage isdominated by Ca-amphibole magnesio-hastingsite. The
T-position is substantially occupied by TAl, reaching 1.309–1.497 apfu. The Mg/(Mg + Fe tot) ratio and
F contents are relatively low, reaching 0.658–0.694
and 0.385–0.514 apfu, respectively. Diopside and250

rarely magnesio-hastingsite are occasionally replacedby ferri-winchite (Na–Ca-amphibole) and actinolite(Ca-amphibole). Apart from TAl (< 0.465 apfu), subtly
lower Fe tot (0.996–1.640 apfu) and F (0.205–0.411
apfu), they are almost isochemical with magnesiohastingsite.

Amphibole and pyroxene in carbonatite-like marbles from Bližná

Tab. 3 Representative chemical analyses of amphiboles.
speciessample/analysis
P2O5 (wt. %)
SiO2
TiO2
Al2O3
V 2O 3
Cr2O3
MnO
Fe2O3*
FeO*
FeOtot
MgO
NiO
ZnO
CaO
SrO
BaO
Na2O
K 2O
F
Cl
H2O*
Total
T-siteP (apfu)Si
Al
Fe3+
C-site
Ti
Al
V
Cr
Fe3+
Fe2+
Mn2+
Mg
B-siteCa
SrBaNa
A-siteNa
K
W-siteFOH
assemblage

primary
Rht
Rht
Tr
Rht
Rht
Fktp
Act
Fwnc
Act
Mhst Mhst Mhst
BLC4/ BLC2/ BLC2/ BLC6/ BLC3/ BLC6/ BLC6/ BLC6/ BLC3/ BLC7/ BLC7/ BLC7/
86-16 128-16 119-16 35-21 45-21 98-16 23-21 27-21 50-21 69-21 74-21 83-21
0.01
0.03
0.00
–
–
0.00
–
–
–
–
–
–
55.94 54.84 57.83 53.55 55.45 50.55 56.24 56.63 56.84 45.39 44.80 45.25
0.27
0.16
0.00
0.28
0.47
0.37
0.16
0.20
0.09
0.79
0.24
0.27
1.16
2.38
0.02
2.34
1.63
4.49
0.87
0.94
0.03
8.56
9.49
8.88
0.04
0.00
0.00
–
–
0.01
–
–
–
–
–
–
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.01
0.00
0.00
0.01
0.24
0.12
0.10
0.32
0.21
0.28
0.34
0.31
0.30
0.52
0.44
0.40
2.67
0.89
0.56
3.33
3.75
5.72
0.81
2.24
2.47
4.58
7.23
6.32
0.17
0.00
0.00
2.66
1.70
2.37
5.54
4.41
6.55
7.93
6.21
7.04
2.57
0.80
0.50
5.66
5.07
7.52
6.27
6.42
8.77 12.06 12.71 12.73
22.43 23.47 23.64 20.34 21.18 19.00 20.07 19.77 18.82 14.53 14.65 14.77
0.01
0.02
0.00
0.12
0.00
0.01
0.00
0.01
0.01
0.00
0.07
0.03
0.02
0.00
0.03
0.11
0.31
0.00
0.03
0.08
0.01
0.08
0.01
0.00
8.58
9.68 10.46
8.84
8.82
9.38 10.52
9.88 10.20
9.65 10.02
9.99
–
–
–
0.03
0.03
–
0.00
0.00
0.00
0.00
0.00
0.00
–
–
–
0.02
0.01
–
0.00
0.00
0.00
0.04
0.11
0.09
4.41
4.32
3.16
4.54
4.37
3.91
3.00
2.80
2.52
4.52
4.71
4.22
0.76
0.51
0.19
0.79
0.62
0.81
0.13
0.18
0.02
0.69
0.87
0.83
1.71
1.61
1.24
1.47
1.56
1.30
0.91
0.94
0.78
0.92
0.95
0.89
0.01
0.03
0.02
0.00
0.00
0.00
0.01
0.02
0.02
0.02
0.02
0.01
1.34
1.49
1.63
1.43
1.43
1.48
1.71
1.70
1.76
1.60
1.61
1.63
99.75 99.53 98.87 100.16 101.52 99.67 100.34 100.09 100.41 99.81 101.44 100.65

secondary
Mrbk Mrbk Fwnc Fwnc
BLC3/ BLC3/ BLC5/ BLC7/
47-21 52-21 25-16 79-21
–
–
0.01
–
55.42 55.81 53.83 55.07
0.09
0.10
0.17
0.10
0.25
0.31
2.70
2.02
–
–
0.03
–
0.02
0.00
0.00
0.01
0.04
0.05
0.32
0.27
15.08 17.49
5.00
5.70
8.92
5.78
5.77
8.61
22.49 21.53 10.26 13.75
10.11 10.37 17.29 14.65
0.00
0.10
0.04
0.00
0.06
0.18
0.16
0.05
1.09
0.81
9.39
7.07
0.00
0.03
–
0.03
0.00
0.00
–
0.00
7.25
7.10
3.12
4.12
0.09
0.09
0.30
0.05
0.28
0.29
0.61
0.45
0.02
0.00
0.02
0.01
1.94
1.96
1.83
1.88
100.67 100.48 100.57 100.09

0.001
7.790
0.190
0.019

0.004
7.619
0.377
0.000

0.000
8.000
0.000
0.000

–
7.565
0.389
0.046

–
7.673
0.266
0.060

0.000
7.223
0.756
0.021

–
7.873
0.127
0.000

–
7.911
0.089
0.000

–
7.979
0.006
0.015

–
6.682
1.318
0.000

–
6.510
1.490
0.000

–
6.612
1.388
0.000

–
8.000
0.000
0.000

–
8.000
0.000
0.000

0.001
7.611
0.388
0.000

–
7.856
0.144
0.000

0.028
0.000
0.004
0.000
0.260
0.020
0.031
4.657

0.017
0.013
0.000
0.000
0.093
0.000
0.016
4.861

0.000
0.003
0.000
0.000
0.058
0.000
0.014
4.876

0.030
0.000
–
0.000
0.308
0.315
0.063
4.284

0.049
0.000
–
0.000
0.330
0.196
0.055
4.370

0.040
0.000
0.001
0.000
0.594
0.283
0.034
4.048

0.017
0.016
–
0.000
0.085
0.649
0.045
4.188

0.021
0.066
–
0.000
0.236
0.515
0.046
4.117

0.010
0.000
–
0.001
0.245
0.769
0.037
3.939

0.087
0.167
–
0.000
0.508
0.976
0.073
3.188

0.027
0.135
–
0.000
0.791
0.754
0.063
3.173

0.030
0.142
–
0.001
0.695
0.861
0.053
3.218

0.010
0.043
–
0.002
1.638
1.077
0.012
2.175

0.011
0.053
–
0.000
1.887
0.693
0.037
2.217

0.018
0.061
0.004
0.000
0.532
0.682
0.060
3.644

0.011
0.196
–
0.001
0.612
1.028
0.038
3.115

1.280
–
–
0.720

1.441
–
–
0.559

1.551
–
–
0.449

1.337
0.003
0.001
0.659

1.307
0.002
0.001
0.690

1.436
–
–
0.564

1.577
0.000
0.000
0.423

1.479
0.000
0.000
0.521

1.534
0.000
0.000
0.466

1.522
0.000
0.002
0.475

1.561
0.000
0.006
0.433

1.564
0.000
0.005
0.431

0.169
0.000
0.000
1.831

0.124
0.002
0.000
1.873

1.423
–
–
0.577

1.081
0.002
0.000
0.917

0.471
0.135

0.604
0.090

0.398
0.034

0.584
0.143

0.481
0.109

0.518
0.147

0.392
0.023

0.236
0.031

0.218
0.003

0.815
0.130

0.895
0.162

0.766
0.154

0.198
0.017

0.100
0.016

0.278
0.054

0.221
0.008

0.758
1.242
RF

0.713
1.384
RF

0.549
1.505
RF

0.656
1.344
AD

0.684
1.316
AD

0.586
1.414
AD

0.404
1.596
AD

0.420
1.580
AD

0.350
1.650
AD

0.433
1.567
HD

0.441
1.559
HD

0.415
1.585
HD

0.133
1.867
AD

0.130
1.870
AD

0.277
1.723
HD

0.208
1.792
HD

Calculations are based on the sum of cations in sites T+C = 13 apfu, or Si = 8 apfu; fields marked with a dash were not analyzed; * – calculated
from stoichiometry.

251

Pavlína Radková, Milan Novák, Jan Cempírek, Stanislav Houzar, Radek Škoda

252

Amphibole and pyroxene in carbonatite-like marbles from Bližná

Fig. 8 Compositional variability of amphiboles. Symbols are the same as in Fig. 7.

4.2.2. Pyroxene and other associatedminerals
The minerals associated with amphiboles – pyroxene,
olivine, phlogopite and albite – also show large compositional variations and unusual compositions (Tab. 4;
Fig. 9). Diopside evolves from Na, Fe-poor (0.80 wt. %FeOtot, 0.024 apfu Fe) in the RF-assemblage to Na, Fe
Fig. 7 Classification diagrams for the individual amphibole assemblages(a–d after Hawthorne et al. 2012, and e–g after Leake et al. 1997).
a – classification diagram discerning calcium, sodium–calcium, andsodium amphiboles. b –, e – classification diagrams for calcium amphiboles. c –, f – classification diagrams for sodium–calcium amphiboles.
d –, g – classification diagrams for sodium amphiboles. The heavy solid
black line is a two-dimensional section of amphibole composition space,
the thick solid lines show the possible range of amphibole compositionsin the respective subgroup (for details, see Hawthorne et al. 2012). Marf
= magnesio-arfvedsonite.

enriched (8.55–5.37 wt. % FeO tot; 0.268–0.168 apfuFe) in the AD-assemblage and Na, Fe-rich (9.53–11.07
FeO tot; 0.294–0.343 apfu Fe) in the HD-assemblage.
A positive correlation of Fe3+ with Na indicates the general diopside–aegirine solid solution, with the aegirine
component in diopside reaching up to 17 mol. %. Within
the individual assemblages, the diopside component israther stable (Fig. 9a) and the major substitution can be
the best expressed by the (NaFe3+)(CaFe2+)–1 vector that
represents hedenbergite–aegirine substitution.
Calcite in all three assemblages (Tab. 5) shows a variable degree of enrichment in MgO (up to 3.49, 0.47, 0.71
wt. %), SrO (up to 0.39, 0.55 and 0.33 wt. %), MnO (upto 0.55, 0.92, and 0.52 wt. %), BaO (up to 0.33, 0.17, and0.21 wt. %) and FeO (up to 0.59, 0.58, and 0.67 wt. %in RF, AD, and HD assemblages, respectively). Dolomite
present in the RF-assemblage also shows elevated SrO(≤ 0.14 wt. %) and MnO (≤ 0.57 wt. %) contents.
253

Pavlína Radková, Milan Novák, Jan Cempírek, Stanislav Houzar, Radek Škoda

Tab. 4 Representative chemical analyses of pyroxene, forsterite, phlogopite and albite.
sample/analysis
P2O5 (wt. %)pyroxene
BLC1/ BLC6/ BLC6/ BLC3/ BLC5/ BLC7/ BLC7/
14-16 110-16 30-21 44-21 63-16 67-16 92-21
0.01
0.02
–
–
0.04
0.00
–

forsterite
BLC1/ BLC4/
20-16 15-21
0.03–

phlogopite
BLC4/ BLC4/ BLC7/ BLC7/
1-21
2-21
67-21 81-21––––

albite
BLC5/
29-16
0.00

SiO2

55.88

53.84

54.10

53.99

53.37

53.73

52.57

42.81

39.56

42.40

42.09

37.34

37.44

67.36

TiO2

0.04

0.01

0.03

0.08

0.15

0.01

0.03

0.02

0.00

0.55

0.57

2.59

1.21

–

Al2O3

0.66

0.08

0.00

0.31

1.90

1.16

1.67

0.00

0.00

11.52

11.12

13.52

13.12

19.37

0.01

0.03

–

–

0.00

0.00

–

0.00

–

0.00

0.01

0.03

0.00

–

Cr2O3

0.00

0.00

0.02

0.01

0.00

0.00

0.00

0.00

0.00

–

–

–

–

Fe2O3*

0.78

2.93

5.95

6.41

7.42

4.83

8.86

FeO*

0.09

3.42

0.90

2.11

3.63

5.19

2.04

FeOtot

0.80

6.06

6.25

7.88

10.30

9.54

10.02

3.01

13.53

3.78

3.82

14.28

12.50

MgO

17.93

14.86

15.20

13.74

11.30

12.01

11.65

55.02

44.83

25.79

25.04

16.16

17.61

–

CaO

24.93

22.22

22.42

22.19

19.33

19.74

20.36

0.03

0.03

0.02

0.09

0.05

0.00

0.27

MnO

0.19

0.43

0.51

0.33

0.33

0.48

0.49

0.57

0.95

0.03

0.03

0.14

0.06

–

NiO

0.00

0.03

0.00

0.05

0.00

0.00

0.00

0.01

0.00

0.00

0.02

0.03

0.00

–

ZnO

0.10

0.03

0.06

0.07

0.00

0.11

0.00

0.00

0.26

0.02

0.04

0.00

0.03

–

SrO

–

–

0.03

0.00

–

–

0.02

–

0.00

0.00

0.00

0.00

0.00

–

BaO

–

–

–

–

–

–

–

–

0.00

0.98

0.93

3.01

5.66

0.35

Na2O

V 2O 3

–
0.50
0.45

0.56

1.19

1.60

1.98

3.26

2.53

2.91

0.02

0.00

0.75

0.46

0.40

0.73

11.49

K 2O

0.00

0.02

0.00

0.00

0.02

0.01

0.00

0.00

0.01

9.11

9.22

7.93

6.43

0.06

F

–

–

–

–

–

–

–

0.11

0.00

2.78

1.42

0.76

1.08

–

Cl

–

–

–

–

–

–

–

0.01

0.02

0.01

0.03

0.03

0.06

–

2.83

3.40

3.28

3.24

H2O*
Total

101.1999.11 100.81 101.27 100.75

99.79 100.60

101.6599.19

100.56

98.26

99.54

99.17

99.35

P (apfu)

0.000

0.001

–

–

0.001

0.000

–

0.001

0.000

–

–

–

–

0.000

Si

1.993

1.999

1.974

1.973

1.967

1.998

1.944

1.004

0.999

3.021

3.049

2.845

2.875

2.978

Ti

0.001

0.000

0.001

0.002

0.004

0.000

0.001

0.000

0.000

0.030

0.031

0.148

0.070

–

Al

0.028

0.004

0.000

0.013

0.083

0.051

0.073

0.000

0.000

0.967

0.949

1.214

1.187

1.009

V

0.000

0.001

–

–

0.000

0.000

–

0.000

0.000

0.000

0.000

0.000

0.000

–

Cr

0.000

0.000

0.001

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.000

0.002

0.000

Fe3+

0.021

0.082

0.163

0.176

0.206

0.135

0.247

Fe2+

0.003

0.106

0.027

0.064

0.112

0.161

0.063

0.059

0.286

0.225

0.232

0.910

0.803

Mg

0.953

0.822

0.827

0.748

0.621

0.666

0.642

1.923

1.688

2.739

2.704

1.835

2.016

-

Ca

0.953

0.884

0.876

0.869

0.763

0.787

0.807

0.001

0.001

0.002

0.007

0.004

0.000

0.013

Mn

0.006

0.013

0.016

0.010

0.010

0.015

0.015

0.011

0.020

0.002

0.002

0.009

0.004

–

Ni

0.000

0.001

0.000

0.001

0.000

0.000

0.000

0.000

0.000

0.000

0.001

0.002

0.000

–

Zn

0.003

0.001

0.002

0.002

0.000

0.003

0.000

0.000

0.005

0.001

0.002

0.000

0.002

–

Sr

–

–

0.001

0.000

–

–

0.000

0.000

0.000

0.000

0.000

0.000

0.000

–

Ba

–

–

–

–

–

–

–

0.000

0.000

0.027

0.026

0.090

0.170

0.006

Na

0.039

0.086

0.113

0.140

0.233

0.183

0.208

0.001

0.000

0.103

0.064

0.058

0.109

0.985

K

0.000

0.001

0.000

0.000

0.001

0.000

0.000

0.000

0.000

0.828

0.852

0.771

0.630

0.003

F

–

–

–

–

–

–

–

0.008

0.000

0.627

0.325

0.184

0.263

–

Cl

–

–

–

–

–

–

–

0.000

0.001

0.001

0.003

0.003

0.008

–

–
0.037

OH
1.343 1.641 1.665 1.659
assemblage
RF
AD
AD
AD
HD
HD
HD
RF
RF
RF
RF
HD
HD
HD
Formulae calculations of pyroxene and forsterite are based on sum of all cations (4 and 3 apfu, respectively), formulae of micas are based on 12
anions. Albite formula is based on 4 anions. Fields marked with a dash were not analyzed; * – calculated from stoichiometry.

Forsterite from the thin sections BLC 1 and BLC 2
is Fe-poor (2.87–3.01 wt. % FeOtot; 0.058–0.062 apfu
Fe 2+ ) whereas BLC 4 is Fe-enriched (13.34–13.53
wt. %; 0.286–0.282 apfu Fe2+). Phlogopite evolves from254

F-rich (0.627–0.325 apfu) and Fe-poor (0.225–0.232apfu) phlogopite in BLC 4 (RF) to Ba, Fe, Ti-enriched
phlogopite in BLC 7 (HD; Fig. 9b). Albite from the
HD-assemblage is Ca-poor (0.05–0.40 wt. % CaO) andAmphibole and pyroxene in carbonatite-like marbles from Bližná

K-poor (0.04–0.11 wt. % K 2O) but enriched in Ba (≤0.69 wt. % BaO) and Fe (≤ 0.50 wt. % Fe 2O3tot).

5. Discussion

5.1. Nomenclature of amphiboles
Amphiboles found in the individual assemblages wereclassified using the scheme by
Hawthorne et al. (2012) basedon the sum of octahedrally-coordinated trivalent cations and Ti –(Al + Fe3+ + 2Ti). This classification differs from the earlier one
in some cases based on the Si
content (Leake et al. 1997). Bothschemes are shown in Fig. 7; themain differences include:
1) amphibole classified as magnesio-hastingsite falls to the
Fe3+-rich edenite field in Leake's (1997) classification
due to its relatively high Si(> 6.5 apfu).
2) analyses plotting near the ferri-katophorite–richterite border of the Hawthorne et al.
(2012) classification, in somecases fall within the richterite
field (Fe3+-rich richterite), rarely in ferri-katophorite field.
The examined amphibole assemblages show the advantage ofsimultaneous use of both schemes
for petrological studies as the differences help distinguish anomalous compositions. Classification of the amphiboles found inBližná is slightly complicatedbecause their contents of Na at
the B-site typically fall near the
0.5 apfu BNa boundary (Fig. 7a)that divides calcic amphiboles
from sodic–calcic amphiboles(Hawthorne et al. 2012). In somecases, it is necessary to use additional adjectives and indicate

the transitional composition (e.g., Na-rich actinolite toferri-winchite) as the bare mineral name would lack the
petrological information.

5.2. Substitutions and compositional variationsin amphiboles and associated minerals
In general, the composition of amphiboles evolves from
tremolite to richterite or from tremolite to magnesio‑rie-

Fig. 9 Composition of pyroxene andphlogopite; a – clinopyroxene in theBližná assemblages, compared to the
published data (after Reguir et al. 2012);b – composition of phlogopite in theBližná assemblages.

255

Pavlína Radková, Milan Novák, Jan Cempírek, Stanislav Houzar, Radek Škoda

Tab. 5 Representative chemical analyses of carbonates.
sample/analysis
MgO (wt . %)calcite
BLC2/ BLC4/ BLC3/ BLC7/
122-16 33-21 55-21 78-21
3.49
1.43
0.47
0.64

dolomite
BLC4/ BLC2/
88-16 130-16
18.97 19.51

CaO

51.66

52.48

54.11

54.17

30.65

31.22

MnO

0.27

0.50

0.92

0.52

0.57

0.28

FeO

0.15

0.58

0.58

0.67

1.91

0.37

SrO

0.12

0.35

0.00

0.33

0.14

0.06

BaO

0.00

0.33

0.17

0.04

0.00

0.00

CO2

44.66

44.18

43.60

44.10

46.35

46.23

Total

100.34

99.85

99.85

100.46

98.58

97.67

Mg (apfu)

0.085

0.036

0.012

0.016

0.894

0.922

Ca

0.908

0.943

0.966

0.964

1.038

1.060

Mn

0.004

0.007

0.013

0.007

0.015

0.007

Fe2+

0.002

0.008

0.008

0.009

0.051

0.010

Sr

0.001

0.003

0.000

0.003

0.003

0.001

Ba

0.000

0.000

0.000

0.000

0.000

0.000

C

1.000

1.000

1.000

1.000

2.000

2.000

assemblage

RF

RF

AD

HD

RF

RF

Formula calculations are based on cation sums (1 apfu for calcite,
2 apfu for dolomite).

beckite (Fig. 7a, 8d); this is characterized by the exchange of Na for Ca via substitution (ANaBNa)1(A□BCa)–1
or increase of Natot along with Fe3+ content, respectively(Fig. 8d). The two exchanges are accompanied by homovalent substitutions such as Fe2+1Mg-1, F1(OH)–1 andto a lesser extent, also Fe3+1Al–1 (Fig. 8a–c). The increaseof richterite component is accompanied by the increaseof Mg/(Mg + Fe2+) and F contents, whereas the increaseof trivalent cations at the octahedral site is followed bytheir decrease (Fig. 8a–c). Most amphiboles are fairly
heterogeneous to estimate compositional trends of individual generations; however, the amphiboles in themagnesio-hastingsite + diopside assemblage follow thesubstitution (ANaCR2+ )1(A□CR3+)–1 along with Tschermak’s
substitution (CR3+TAl3+)1(CR2+TSi)–1; both are documented
by the variable ANa, C(Fe3+ + Al + 2Ti), Fe3+/(Fe3+ + Al) and
Si contents (Figs. 7b, c, e, f and 8d).
There is a general increase in Fe contents in amphiboles in the RF via the AD to the HD-assemblage,
with an obvious overlap of the latter two assemblages(Fig. 8a–d). Late magnesio-riebeckite from the ADassemblage (BLC 3) shows ANa-, and Fe3+-enrichment
towards magnesio-arfvedsonite (Fig. 7d,g). The concentrations of F generally decrease with increasing Fe,from F-rich richterite to F-poor magnesio-riebeckite (Fig.
8b). Well-defined negative correlation Fe/F indicatesa potential Fe/F avoidance in the amphibole structure(e.g.,Rosenberg and Foit 1977) known in other silicates(e.g., biotite – Mason 1992); however, lower availabilityof F in late fluids facilitating origin of magnesio-riebeckite is more likely due to the absence of F in late-stage
256

minerals. Concentrations of Na are variable but similarin all assemblages except for the late Na-rich magnesioriebeckite (Fig. 8d). Magnesio-hastingsite from the HDassemblage is enriched in Al (Fig. 8a–d).
The amphibole composition (Fig. 10a) partially overlaps with the carbonatite field defined by Reguir et al.
(2012) and the amphibole composition range from theFir carbonatite, Canada (Chudy 2013); however, theoverlap is relatively poor and does not clearly indicate
the relationship of the Bližná carbonatite-like marble tocarbonatites.
Diopside compositions evolve from Al-poor diopside in the RF-assemblage to the diopside with up to
17 mol. % of aegirine component in the HD-assemblage(Tab. 4, Fig. 9a). They generally fall into the carbonatitefield defined by Reguir et al. (2012). However, pyroxenesof similar composition are not uncommon in alkaline
igneous rocks (e.g., Martin 2007). Calcite in all threeassemblages has elevated concentrations of Mg, Sr, Mn,
Ba and Fe and this enrichment is similar to carbonatesfrom the Fir carbonatite, British Columbia, Canada(Chudy 2013). The rock-forming calcite shows elevatedSr and high Mn abundances (Tab. 5), characteristicof carbonatites, which are uncommon in sedimentarycarbonates and distinctly higher from ordinary marbles
in the Moldanubian Zone. The latter typically contain
low levels of Sr and Mn not exceeding 100 ppm (e.g.,
Veizer et al. 1992). Yang and Le Bas (2004) suggested
that the Sr and Mn contents of carbonate minerals can beused to discriminate igneous rocks from metamorphosed
sedimentary carbonates. Ca, K-poor albite enriched in
Ba and Fe from the HD-assemblage is somewhat uniquein its composition; its BaO and Fe2O3 contents (≤ 0.69
wt. % BaO and ≤ 0.50 wt. % Fe2O3tot) seem to be thehighest reported in Ca,K-poor albite up to date. Elevatedamounts of Fe2O3 in plagioclase (0.24 wt. % in albite
Ab100 and up to 0.44 wt. % Fe2O3 in Ca-rich plagioclase
An77Ab20Or1) were reported from Mont Saint Hilaire alkaline pegmatites (Schilling et al. 2011), from Thor Lakealkaline pegmatite (in albite Ab98; up to 0.20 wt. % Fe =0.28 wt. % Fe2O3tot; De St. Torre and Smith 1988), andfrom Bayan Obo carbonatite dykes (0.20 FeOtot = 0.22
wt. % Fe2O3tot in Ab100; Le Bas et al. 1992). The presenceof Fe-enriched plagioclase seems to be significant inalkaline rocks; however, a systematic study is needed tomake conclusive interpretations.

5.3. Comparison of amphiboles and otherminerals from ordinary metacarbonates ofthe Moldanubian Zone (Bohemian Massif)
and banded metacarbonate in Bližná
Amphiboles from the examined carbonatite-like marble
in Bližná differ significantly from amphiboles in ordi-

Amphibole and pyroxene in carbonatite-like marbles from Bližná

Fig. 10 Comparison of Bližná amphiboles composition to a –, b – the amphiboles from carbonatites (after Reguir et al. 2012; Hogarth 1989; Chudy 2013) and (a–e) to the amphiboles from ordinary marbles in the Bohemian Massif (Houzar 2004; Houzar et al. 2017) and marble hosted-rubydeposits (Garnier et al. 2005, 2008; Feneyrol et al. 2012; Dzikowski et al. 2014).

nary marbles of the Moldanubian Zone as well as othergeological units (for instance Olešnice unit, Velké Vrbno
unit, Vratěnín unit, Vranov unit and other localities in theČeský Krumlov unit; Novák 1989; Houzar 2004), where
typically calcic amphiboles (tremolite, edenite, pargasite,
magnesio-hornblende) occur (Fig. 10). The major dif257

Pavlína Radková, Milan Novák, Jan Cempírek, Stanislav Houzar, Radek Škoda

ferences in the composition include significantly higher
Na, Fe, and F contents in Bližná (Fig. 10). Only scarcely,
Na-bearing fluor-tremolite (< 0.5 apfu Natot) associatedwith fluor-uvite in hydrothermal vein cutting marble was
identified in Muckov; it is the only amphibole showing
a slight compositional similarity to amphiboles from thecarbonatite-like marble in Bližná. In the RF-assemblage,
chemical compositions of diopside and forsterite arecomparable to ordinary dolomite marbles except for the
BLC 4 sample, where forsterite is enriched in Fe. However, the composition of the associated richterite (Tab. 3)
markedly differs from the usual tremolite in ordinary
marbles. Similarly, diopside with high aegirine component and Ba-enriched phlogopite from AD- and HD-assemblage are distinct from their counterparts described inordinary marbles, the latter mainly by its high Fe contents(cf. Doležalová et al. 2006; Houzar and Cícha 2016;
Houzar et al. 2017).

5.4. Origin of the Bližná mineral assemblages
The Bližná marble shows mostly plastic deformationand dynamic recrystallization of carbonates along withbrittle deformation of silicate bands. The calcite + dolomite symplectites observed in Bližná are typical for somecarbonatites (e.g., Chudy 2013; Chakhmouradian et al.
2016a). They are interpreted as an exsolution texture after
a high-temperature carbonate solid solution; the texture
is typically magmatic (Chakhmouradian et al. 2016a).
Chudy (2013) calculated the carbonate solvus temperatures and concluded that they mostly represent regional
peak-metamorphic conditions, but part of the samples
represented the original magmatic crystallization; theCal + Dol exsolution texture is a result of retrograde reequilibration of the carbonatites.
The observed amphibole parageneses and compositions do not indicate prograde overprint of the potential
magmatic amphibole assemblages; similarly, Reguir et al.
(2012) and Chudy (2013) interpret most amphibole compositions in carbonatites as magmatic. In Bližná, euhedral
amphiboles seem to be in equilibrium with forsterite,
diopside or Ba, Fe-rich phlogopite, and their formation isearlier or coeval with crystallization of oxides (Fig. 5f).
In the HD assemblage, albite formed in disequilibriumwith diopside resulting in reaction Ab + Di = Mhst; excess of albite allowed the formation of the Mhst + Abintergrowths (Fig. 6d). The secondary ferri-katophorite torichterite forming after diopside and magnesio-riebeckite
overgrowths around Na-rich actinolite and ferri-winchiterequire input of Na, F and minor Fe and Na and Fe3+
under oxidizing conditions, respectively, probably during
post-magmatic evolution of the rock. On the other hand,the breakdown of Mhst to ferri-winchite might be related
to retrograde hydration reactions in the marble, similar258

to the formation of serpentine and talc at the expense of
Mg-silicates (Fig. 6b).
Formation of late sodic amphibole (magnesio-riebeckite, magnesio-arfvedsonite or ferri-nyboite) is characteristic of carbonatites attributed to autometasomatic overprint
by late-stage alkaline fluids (Hogarth 1989; Chakhmouradian and Zaitsev 2002; Reguir et al. 2012, Chudy 2013);
origin from Na, Fe-rich fluids agrees with the observed
replacement of actinolite by magnesio-riebeckite in theBližná carbonatite-like marble (Fig. 5e).

5.5. Origin of carbonatite-like marble
We discuss the potential origin of the carbonatite-likemarble from Bližná based mainly on the chemicalcomposition of amphiboles and associated minerals,
their compositional trends, and the mineral assemblages
and textural relations of minerals. Accessory minerals(Tab. 2) are considered, too, although these have not beenstudied in detail in this paper. An obvious metamorphic
overprint hampers the evaluation of the potential originof carbonatite-like marble. However, we examine several
potential options.
(i) Metacarbonates (potentially with Na- and Na, Cacarbonates and sulfate admixture) are a product of sedimentation in a limnic (playa) and/or hypersaline lagoonalenvironments with potential production of evaporites.
Accessory sodic, and sodic-calcic amphiboles andsodic-ferric pyroxenes in these particular sediments may
be of detritic or diagenetic origin (Milton and Eugster
1959; Fortey and Michie 1978; Mange-Rajetzky 1981;
Behr et al. 1983; Decarreau et al. 2004). Metamorphic
amphiboles that reflect the input of evaporite component(commonly associated with scapolite) are known frommarble-hosted ruby and tsavorite deposits (e.g., Garnier
et al. 2005, 2008; Feneyrol et al. 2012; Dzikowski et al.
2014). However, a total absence of Cl and/or B in theassemblage (e.g., marialite and tourmaline describedfrom other marbles within the Český Krumlov Unit andelsewhere in the Bohemian Massif; e.g., Kadounová
1987; Kříbek 1988; Kříbek et al. 1997; Bačík et al. 2012;
Krmíček et al. 2021) does not support the hypothesis
for marine evaporite source. Moreover, marbles withsignificant evaporite component typically contain amphiboles with tremolite–pargasite or tremolite–edenite
solid solution with variable A,B(Na + K) < 1 apfu, elevatedAl (Fig. 10d), variable F and locally high K2O contents(Fig. 10b), and commonly very low Fetot/(Mg + Fetot) andFe3+/CR3+ (Fig. 10c,e). These amphibole compositions
are distinctly different from magnesio-riebeckite and theearly amphiboles from Bližná that represent primarily
actinolite–richterite solid solution (Fig. 7, 10d).
(ii) Admixture of volcanodetritic component (basic
tuffs, tuffites or mixed sediments) during carbonate

Amphibole and pyroxene in carbonatite-like marbles from Bližná

sedimentation (Kadounová 1987; Hladíková et al. 1993;
Drábek and Stein 2015; Drábek et al. 2017) is an additional option. Tholeitic amphibolites are relatively common in the Český Krumlov Unit; however, alkaline rocks
such as metabasites which would represent a source ofsome components (Na, Ba, Fe, F) in the marble have notbeen found in the Černá region (Patočka 1991; Janoušek
et al. 2008). Nevertheless, their potential presence inthis region cannot be discounted. Besides the presenceof Na, Fe-rich silicate assemblages, this option does not
explain the presence of Nb-oxides (Drábek et al. 2017)
nor the anomalous composition of carbonates.
(iii) Metamorphosed carbonatites enclosed in ordinary
sedimentary metacarbonate show distinct geochemicalsignatures (Drábek et al. 1999; Novák et al. 2012), andare characterized by the occurrence of Na, Fe, F-enrichedamphiboles, Sr, Mn-enriched carbonates (Tucker andWright 1990; Veizer et al., 1992; Yang and Le Bas 2004;
Cheng et al. 2010; Chakhmouradian et al. 2016b), anddiopside with elevated aegirine component (Reguir etal. 2012). The Bližná occurrence shows a remarkablesimilarity with the Fir carbonatite, British Columbia(Chudy 2013), representing a suite of dolomite- andcalcite-dominated carbonatites with variable contentsof silicates, apatite and sulfides, and fenitized mafic
country rocks, metamorphosed under amphibolite-facies
conditions. Both localities feature Sr, Mn-enriched
Fe, Mg-bearing calcite, amphiboles ranging from Narich actinolite–edenite and magnesio-hastingsite throughrichterite–winchite–katophorite to magnesio-riebeckite(–magnesio-arfvedsonite–nyböite), as well as the clinopyroxene–albite assemblage (retrograde, formed at theexpense of magnesio-hastingsite in the Fir carbonatite).
The Bližná amphiboles are similar to those from carbonatites in their high Na and elevated Fe contents but
differ in lower Al abundances. In carbonatites, assimilation of crustal material is regarded as a possible source ofAl (e.g., Chakhmouradian and Zaitsev 2002); its limited
presence in Bližná may therefore indicate the relatively
pristine composition of the examined small part of themetacarbonate sequence.
(iv) Sodium-rich metasomatites characterized bymineral assemblages with Na, Fe, F-enriched amphiboles,
diopside with high aegirine component and albite (e.g.,
Albino 1995; Potts 2000; Shi et al. 2003; Yiming and
Daxin 2005; Tsikos and Moore 2005; Hogarth 2016) areanother potential option. Drábek and Stein (2015) claimthat there is no textural or other geological evidence forthe input of fluids from the host rocks; the role of external
fluids needs to be assessed by the petrographic study ofcarbonates. We observed hydrothermal overprint in thinsections (e.g., Fig. 5b–e, 6a–c), but the fluids were notparticularly rich in F and their Fe content increases withthe decrease of F (Fig. 10c).

6. Conclusions
Three distinct mineral assemblages were recognized incarbonatite-like marble from Bližná – richterite + forsterite assemblage (Rht + Fo + Cal ˃ Dol ˃ Phl + Di), Na‑richactinolite + diopside assemblage (Di + Act + Rht + Cal ˃Phl) and magnesio-hastingsite + diopside assemblage(Mhst + Di + Cal ˃ Ab + Phl). The following amphibole
species were recognized in the individual assemblages:
RF – (richterite > ferri-winchite > tremolite, edenite), AD– (actinolite > ferri-winchite; richterite > ferri-katophorite; magnesio-riebeckite), HD – (magnesio-hastingsite)using the scheme of Hawthorne et al. (2012).
The individual mineral assemblages differ especiallyin Mg/(Mg + Fe tot) ratio and F concentrations. Diopside contains up to 17 mol. % of the aegirine component and albite is Fe, Ba-enriched. The compositional
ranges of amphibole and diopside are very similar tocarbonatites s.l. and suggest highly alkaline conditions
typical for carbonatites.The following possible originof the carbonatite-like marble from Bližná are examined: (i) metacarbonates potentially with Na- andNa, Ca-carbonates and sulfate admixture; (ii) admixture of volcanodetritic component during carbonate
sedimentation; (iii) metamorphosed carbonatites (or theirdykes) enclosed in ordinary sedimentary metacarbonate;(iv) Na-rich metasomatites characterized by mineral assemblages with Na, Fe, F-enriched amphiboles, diopsidewith high aegirine component and albite. We can exclude(i) marine evaporates rich in Cl or B because amphibole
assemblages are free of Cl and B, whereas the other options (ii), (iii) and (iv) are, in general, possible.
The amphiboles observed in the Bližná carbonatitelike marble are unique within the Bohemian Massif anddistinctly different from amphiboles found in metacarbonates with evaporite component (Fig. 10a–e). A thoroughstudy of the whole mineral assemblage, including isotopic studies, is required to reveal the original protolithof the rock and assess the metamorphic changes in themarble body.
Acknowledgments. The authors dedicate this article tothe late Milan Drábek for his long-term and fundamental research in mineralogy, experimental petrology andeconomic geology, including the examined metacarbonates from Bližná. The authors are grateful for thethorough reviews of the manuscript by D. Zozulya andan anonymous reviewer and for the editorial suggestions
and corrections by J. Kotková. This work was supportedby the research project GAČR 19-17276S to MN, RŠ
and JC. The article appears through the institutional support of long-term conceptual development of research
institutions provided by the Ministry of Culture (ref.
MK000094862) to SH.
259

Pavlína Radková, Milan Novák, Jan Cempírek, Stanislav Houzar, Radek Škoda

References
Albino GV (1995) Sodium Fault metasomatism along Zone,
Sierra Nevada California, USA the Melones Foothills.
Mineral Mag 59: 383–399
Bačík P, Uher P, Cempírek J, Vaculovič T (2012) Magnesian tourmalines from plagioclase-muscovite-scapolite
metaevaporite layers in dolomite marble near Prosetín(Olešnice Unit, Moravicum, Czech Republic). J Geosci
57: 143–153
Behr HJ, Ahrendt H, Martin H, Porada H, Röhrs J,
Weber K (1983) Sedimentology and Mineralogy ofUpper Proterozoic Playa-Lake Deposits in the Damara
Orogen. In: Martin H, Eder FW (eds) Intracontinental
Fold Belts. Case Studies in the Variscan Belt of Europe
and the Damara Belt in Namibia, Springer, Berlin, Heidelberg, pp 577–610
Cháb J, Breiter K, Fatka O, Hladil J, Kalvoda J,Šimůnek Z, Štorch P, Vašíček. Z, Zajíc J, Zapletal J(2008) Brief geology of the basement of the Bohemian
Massif and its Carboniferous and Permian cover. Czech
Geological Survey, Praha, pp 1–283 (in Czech)
Chakhmouradian AR, Zaitsev AN (2002) Calcite amphibole clinopyroxene rock from the Afrikanda complex,
Kola Peninsula, Russia: mineralogy and a possible linkto carbonatites. III. Silicate minerals. Canad Mineral
40: 1347–1374
Chakhmouradian AR, Reguir EP, Zaitsev AN (2016a)
Calcite and dolomite in intrusive carbonatites. I. Texturalvariations. Mineral Petrol 110(2-3): 333–360
Chakhmouradian AR, Reguir EP, Couëslan C, Yang P(2016b) Calcite and dolomite in intrusive carbonatites. II.
Trace-element variations. Mineral Petrol 110: 361–377
Cheng X, Kynický J, Chakhmouradian AR, Qi L, Song W(2010) A unique Mo deposit associated with carbonatites in
the Qinling orogenic belt, central China. Lithos 118: 50–60
Chudy TC (2013) The petrogenesis of the Fir carbonatite
system, east-central British Columbia, Canada. PhD
thesis, University of British Columbia, pp 1–560
Čížek J, Kříbek B, Bouzek F, Hladíková J, Šmejkal V(1984) Izotopic composition of carbonates from graphite
deposits of the Český Krumlov Varied Unit, Moldanubicum. Sborník “Korelace proterozoických a paleozoických stratiformních ložisek” 8: 103–122 (in Czech)
Decarreau A, Petit S, Vieillard P, Dabert N (2004)
Hydrothermal synthesis of aegirine at 200 °C. Eur J Mineral 16: 85–90
Deer WA, Howie RA, Zussman J (1997) Double Chain
Silicates, Rock-Forming Minerals, (2nd edition.) vol. 2B.
The Geological Society, London, UK, pp 764
De St. Torre L, Smith DGW (1988) Cathodoluminescentgallium-enriched feldspars from the Thor Lake raremetal deposits, Northwest Territories. Canad Mineral
26: 301–308
260Doležalová H, Houzar S, Losos Z, Škoda R (2006)
Kinoshitalite with a high magnesium content in sulphiderich marbles from the Rožná uranium deposit, Western
Moravia, Czech Republic. N Jb Min, Abh, 2006 2: 165–171
Drábek M, Stein H (2003) The age of formation of amarble in the Moldanubian Varied Group, Bohemian
Massif, Czech Republic using Re-Os dating of molybdenite. In: Eliopoulos D, et al. (eds) Mineral explorationand sustainable development – Proceed SGA meeting,Athens, 973–976
Drábek M, Stein H (2015) Molybdenite Re–Os dating of
Mo–Th–Nb–REE rich marbles: pre-Variscian processes
in Moldanubian Variegated Group (Czech Republic).
Geol Carpath 66: 173–179
Drábek M, Frýda J, Janoušek V (1999) Regionally metamorphosed carbonatite-like marbles from the VariedGroup, Moldanubian Unit, Bohemian Massif, Czech
Republic, and their Mo–Th–Nb–REE mineralization.
– In: Stanley CJ (ed.): Proceedings of the fifth biennial
SGA meeting and the tenth quadrennial IAGOD meeting,London, pp 635–638
Drábek M, Frýda J, Šarbach M, Skála R (2017) Hydroxycalciopyrochlore from a regionally metamorphic
marble at Bližná, Southwestern Czech Republic. N Jb
Mineral Abh 194: 49–59
Dzikowski TJ, Cempírek J, Groat LA, Dipple GM,
Giuliani G (2014) Origin of gem corundum in calcite
marble: The Revelstoke occurrence in the CanadianCordillera of British Columbia. Lithos 198: 281–297
Feneyrol J, Ohnenstetter D, Giuliani G, Fallick AE,
Rollion-Bard C, Robert JL, Malisa EP (2012) Evidence of evaporites in the genesis of the vanadian grossular ‘tsavorite’deposit in Namalulu, Tanzania. CanadMineral 50: 745–769
Fortey NJ, Michie UMcL (1978) Aegirine of possible
authigenic origin in Middle Devonian sediments in Caithness, Scotland. Mineral Mag 42: 439–442
Frank W, Hammer S, Popp F, Scharbert S, Thoni M(1990) Isotopengeologische Neuergebnisse zur Entwicklungsgeschichte der Bohmischen Masse: Proterozoische
Gesteinsserien und Variszische Hauptorogenese. Osterr
Beitr Met Geoph H3: 185–228
Frank W, Scharbert S, Höck V (1992) Rb/Sr - Untersuchungen an Karbonatgestein der Böhmischen Masse.
FWF - Projekte S4702 und S4704. In: Höck V (ed.)
Schwerpunkteprogramm S47 GEO „Präalpidische Krustein Österreich“ Bericht 1991, pp 9–10
Garnier V, Ohnenstetter D, Giuliani G, Maluski H,
Deloule E, Trong TP, Van LP, Quang VH (2005) Ageand significance of ruby-bearing marble from the Red
River Shear Zone, northern Vietnam. Canad Mineral
43: 1315–1329
Garnier V, Giuliani G, Ohnenstetter D, Fallick AE,
Dubessy J, Banks D, Vinh HQ, Lhomme T, Maluski

Amphibole and pyroxene in carbonatite-like marbles from Bližná

H, Pecher A, Bakhsh KA, Van Long P, Trinh PT,
Schwarz D (2008) Marble-hosted ruby deposits fromCentral and Southeast Asia: Towards a new genetic
model. Ore Geol Rev 34: 169–191
Hawthorne FC, Oberti R, Harlow GE, Maresch WV,Martin RF, Schumacher JC, Welch MD (2012) Nomenclature of the amphibole supergroup. Amer Mineral
97: 2031–2048
Hladíková J, Kříbek B, Macenauer T (1993) Isotopic
composition of sulphidic sulphur in the graphitic depositsof the Bohemian Massif. Věst Čes Geol ústavu 68: 65–71
Hogarth DD (1989) Pyrochlore, apatite and amphibole:
distinctive minerals in carbonatite. – In: Bell, K. (Ed.),
Carbonatites: Genesis and Evolution. Unwin Hyman,
London, pp 105–148
Hogarth DD (2016) Chemical Trends in the Meech Lake,
Québec, Carbonatites and Fenites. Canad Mineral 54(5): 1105–1128
Högelsberger H (1989) Die Marmore und Kalksilikatgesteine der Bunten Serie – Petrologische Untersuchungenund geologische Konsequenzen. Jb Geol B-A 132:
213–230
Houzar S, Cícha J (2016) Chondrodite- and clinohumitebearing marbles of the Podolsko Complex in Písek area
and related F-rich Mg–Si–Ti–Ba–Zr mineral assemblage(Moldanubian Zone, Bohemian Massif). Bull mineralpetrolog Odd Nár Muz (Praha) 24: 33–45 (in Czech)
Houzar S (2004) Metamorphosed carbonate rocks in geology and evolution at the south-eastern margin of theBohemian Massif. Unpublished PhD thesis Masaryk
University Brno, pp 3–155 (in Czech)
Houzar S, Novák M (2002) Marbles with carbonatitelike geochemical signature from variegated units of theBohemian Massif, Czech Republic, and their geologicalsignificance. J Czech Geol Soc 47 (3–4): 103–109
Houzar S, Novák M, Cícha J (2017) Mineral assemblages
and lithology of marbles of the Bohemian part of the
Moldanubian Zone (Bohemian Massif). Bull Mineral
Petrol 25 (2): 113–140 (in Czech)
Janoušek V, Vrána S, Erban V, Vokurka K Drábek
M (2008) Metabasic rocks in the Varied Group of the
Moldanubian Zone, southern Bohemia – their petrology, geochemical character and possible petrogenesis.
J Geosci 53: 31–64
Jenček V, Vajner V (1968) Stratigraphy and relations of
the groups in the Bohemian part of the Moldanubicum.
Krystalinikum 6: 105–124
Kadounová Z (1987) Petrology, petrochemistry and structural evolution of the Městský vrch graphite deposits andits relation to rocks of Český Krumlov Varied Group,
Moldanubicum. Unpublished Diploma thesis Charles
University, pp 1–134 (in Czech)
Krmíček L, Novák M, Trumbull RB, Cempírek J, Houzar
S (2021) Boron isotopic variations in tourmaline frommetacarbonates and associated calc-silicate rocks fromthe Bohemian Massif: Constraints on boron recyclingin the Variscan orogen. Geosci. Frontiers 12: 219–230
Kříbek B (1988) Lithological, structural and metamorphic
development of the graphite deposits in the Český Krumlov varied Group, Moldanubicum. Sborník „HornickáPříbram ve vědě a technice“, geologie, pp 255–270 (inCzech)
Kříbek B, Hladíková J Frýda J (1997) Scapolite andanhydrite-bearing rocks from the Moldanubian zone of
the Bohemian Massif: Metamorphosed exhalites andevaporites. J Czech Geol Soc 42 (3): 62
Le Bas MJ, Kellere J, Kejie T, Wall F, William CT,
Peishan Z (1992) Carbonatite dykes at Bayan Obo, Inner
Mongolia, China. Mineral Petrol 46: 195–228
Leake B E, Woolley AR, Arps CE, Birch WD, Gilbert
MC, Grice JD, Hawthorne FC, Kato A, Kisch HJ,
Krivovichev VG, Linthout K, Laird J, Mandarino
JA, Maresch WV, Nickel EH, Rock NMS, Schumacher JC, Smith DC, Stephenson NCN, Ungaretti
L, Whittaker EJW, Youzhi G (1997) Nomenclature ofamphiboles; report of the Subcommittee on Amphibolesof the International Mineralogical Association Commission on new minerals and mineral names. Mineral
Mag 61 (405): 295–310
Martin RF (2007) Amphiboles in the igneous environment.
Rev Mineral Geochem 67: 323–358
Mange-Rajetzky MA (1981) Detrital blue sodic amphibole
in Recent sediments, southern coast, Turkey. J Geol Soc
138: 83–92
Mason RA (1992) Models of order and iron-fluorine avoidance in biotite. Canad Mineral 30 (2): 343–354
Merlet C (1994) An Accurate Computer Correction Program for Quantitative Electron Probe Microanalysis.
Mikrochim Acta 114/115: 363–376
Milton C, Eugster HP (1959) Mineral assemblages ofGreen River formation. In: Abelson HP (e) Researches
in Geochemistry; John Wiley & Sons: New York, NY,
USA, pp 118–150
Mitchell RH (2005) Carbonatites and carbonatites andcarbonatites. Canad Mineral 43 (6): 2049–2068
Novák M (1989) Metamorphism of dolomite rocks at thenorth-eastern margin of the moldanubicum, Western
Moravia, Czechoslovakia. Acta Mus Morav 74: 7–51
(in Czech)
Novák M, Škoda R, Gadas P, Krmíček L, Černý P(2012) Contrasting origins of the mixed (NYF + LCT)
signature in granitic pegmatites, with examples from
the Moldanubian zone, Czech Republic. Canad Mineral
50: 1077–1094
Patočka F (1991) Geochemistry and Primary Tectonic Environment of the Amphibolites from the Český Krumlov
Varied Group (Bohemian Massif, Moldanubicum). Jb
Geol B – A 134: 117–133
261

Pavlína Radková, Milan Novák, Jan Cempírek, Stanislav Houzar, Radek Škoda

Potts DA (2000) Sodium metasomatism and magnesioriebeckite mineralization in the Wilson Ridge pluton.
UNLV Retrospective Theses & Dissertations 1155: 1–117
Radková P (2017) Mineralogy and petrography of metacarbonate rocks from Bližná near Černá v Pošumaví. Unpublished Ms Thesis, Masaryk University, pp 1–61 (in Slovak)
Reguir EP, Chakhmouradian AR, Pisiak L, Halden
NM, Yang P, Xu C, Kynický J, Couëslan CG (2012)
Trace-element composition and zoning in clinopyroxene– and amphibole-group minerals: Implications for element partitioning and evolution of carbonatites. Lithos
128–131: 27–45
Rosenberg PE, Foit FF (1977) Fe2+–F avoidance in silicates. Geochim Cosmochim Acta 41: 345–346
Šarbach M, Drábek M, Veselovský F (1985) Mo–Th–Nblanthanoide mineralization of marble at Václav mine,Bližná. Geol průzkum 27: 116 (in Czech)
Schilling J, Marks MA, Wenzel T, Vennemann T,
Horváth L, Tarassoff P, Jacob DE, Markl G (2011)
The magmatic to hydrothermal evolution of the intrusive
Mont Saint-Hilaire complex: insights into the late-stage
evolution of peralkaline rocks. J Petrol 52(11): 2147–2185
Schrauder M, Beran A, Hoernes S, Richter W (1993)
Constraints on the Origin and the Genesis of GraphiteBearing Rocks From the Variegated Sequence of theBohemian Massif (Austria). Mineral Petrol 49: 175–199
Shi GH, Cui WY, Tropper P, Chang-Qiu Wang, Gui-Ming
Shu, Haixa Yu (2003) The petrology of a complex sodic
and sodic–calcic amphibole association and its implications for the metasomatic processes in the jadeitite area
in northwestern Myanmar, formerly Burma. Contrib
Mineral Petrol 145: 355–376
Suk M (1974) Lithology of Moldanubian metamorphics.
Čas Mineral Geol 19: 373–389
Tsikos H, Moore JM (2005) Sodic metasomatism in the
Palaeoproterozoic Hotazel iron-formation, Transvaal

262

Supergroup, South Africa: implications for ﬂuid–rockinteraction in the Kalahari manganese ﬁeld. Geoﬂuids
5: 264–271
Tucker ME, Wright VP (1990) Carbonate Sedimentology.
Blackwell Publishing, Oxford, pp 1–482
Veizer J, Plumb KA, Clayton RN, Hinton RW, Grotzinger JP (1992) Geochemistry of Precambrian carbonates: V. late Paleoproterozoic seawater. Geochim
Cosmoch Acta 56 (6): 2487–2501
Veselovský F, Drábek M, Drábková E, Šarbach M(1987) Marbles of carbonatite character from the
Moldanubic Varied group at Bližná, Czechoslovakia.
Proceedings 1st seminar on carbonatites and alkaline
rocks of the Bohemian Massif and ambient regions,
Praha, pp 85–91
Vrána S, Břízová E, Dvořák I, Grundloch J, Holásek
O, Kadlecová R, Krejčí Z, Krupička J, Lysenko V,
Manová M, Nývlt D, Poňavič M, Přechová E, Šrámek
J, Trubač J, Verner K (2010) Explanation to geologicalmap of the Czech Republic 1 : 25 000, Sheet 32-233 Černá
v Pošumaví. Unpublished manuscript, Czech Geological
Survey, Prague, pp 1–125 (in Czech)
Warr LN (2021) IMA–CNMNC approved mineral symbols. Mineral Mag 85 (3): 291–320
Yang XM, Le Bas MJ (2004) Chemical compositions ofcarbonate minerals from Bayan Obo, Inner Mongolia,
China: implications for petrogenesis. Lithos 72 (1–2):
97–116
Yiming Z, Ge B, Daxin L (2005) REE-Nb (Fe, U, Th)bearing alkaline skarns of China. In: Mao J., Bierlein
FP (eds) Mineral Deposit Research: Meeting the Global
Challenge. Springer, Berlin, Heidelberg, pp 507–509
Zoubek V, Fiala J, Vaňková V, Machart J, Stettner G(1988) Moldanubian Region. In: Zoubek V (ed) Precambrian in Younger Fold Belts, John Wiley & Sons,
pp 183–267